PFAS in Onalaska, WI Drinking Water
PFAS data for Onalaska, Wisconsin · 18,000 residents · 1 ZIP code
PFAS is regulated under the Safe Drinking Water Act because of its potential health effects at elevated concentrations; for residents of Onalaska, Wisconsin, the relevant fact is that it has shown up in recent EPA compliance samples — point-of-use filtration is one option residents research, alongside reviewing the utility's published treatment data.
Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-05-14
PFAS in Onalaska Tap Water
PFAS has been detected in Onalaska, Wisconsin drinking water at a maximum level of 0.0042 ppt — below the EPA MCL of 4 ppt (PFOA/PFOS individually).
This analysis covers 18,000 residents across 1 ZIP code in Onalaska.
Onalaska's overall water quality grade is B (78/100).
Is PFAS in Onalaska Water Safe?
PFAS was detected in Onalaska water but currently falls within EPA limits. However, some health organizations argue the EPA MCL may not be protective enough.
If you are concerned, a reverse osmosis or granular activated carbon filter can reduce pfas levels further.
PFAS Levels by ZIP Code
| ZIP Code | PFAS Level | EPA Limit | Status |
|---|---|---|---|
| 54650 | 3 detections | 4 ppt (PFOA/PFOS individually) | OK |
Average pfas level across Onalaska: 3 ppt
Health Effects of PFAS
- Increased risk of kidney and testicular cancer
- Thyroid disease and immune system suppression
- Reproductive problems and reduced fertility
- Elevated cholesterol and liver effects
- Developmental effects in infants and children
Health risk severity: High. Governed by the PFAS National Primary Drinking Water Regulation (2024).
How PFAS Gets Into Drinking Water
- Firefighting foam (AFFF) used at military bases and airports
- Industrial manufacturing (non-stick coatings, stain-resistant fabrics)
- Wastewater treatment plants that receive industrial discharge
- Landfill leachate from PFAS-containing consumer products
What to Do About PFAS in Onalaska Water
- Install a reverse osmosis system (most effective — removes 90%+ of PFAS)
- Granular activated carbon (GAC) filters remove some PFAS compounds
- Look for NSF 53 or NSF 58 certification specifically tested for PFAS
- Pitcher filters with activated carbon provide partial reduction
Look for filters certified under NSF 53 / NSF 58 for pfas removal.